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@#Introduction: Broken glass exhibits unique fracture patterns depend upon the nature of the impact. The fracture patterns provide information like point and angle of impact, direction of force and sequence of firing. Recent studies have shown that the use of shotgun in Malaysia is increasing, yet, the relationship existing among the fracture pattern and the projectile impact factors are not well documented. The objective was to analyse the fracture characteristics on different glass types of variable thickness and distance made by shotgun ammunition. Methods: Soda lime and tempered glass panel with dimension of 12’x 12’ with 3 or 4 mm thickness were shot from various distances of 4, 6 and 8 m from the muzzle end of the shotgun. Samples were analysed under fixed parameters and observations were recorded. Results: It is found that the bullet hole diameter of 4 mm tempered glass were larger compared to 4 mm soda lime glass ranged from 14.33 to 24.17 cm as distance increased. Tempered glass surface also exhibited dicing fragments unlike soda lime glass where only radial fracture patterns are evident. This can be attributed to high inherent strength and ductility that makes the tempered glass remarkably resistant to external force. Conclusion: The findings from this study can lead to distinguish the type of glass through examination of fracture patterns, whether it is soda lime silica or tempered glass. The type of glass and the source of impact can be determined using the fragments, no reconstruction necessary.
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Background@#Available research about the anatomic patterns of intertrochanteric fractures is lacking, and fracture mapping has not previously been performed on intertrochanteric fractures. This study aimed to determine the major trajectories of intertrochanteric fracture lines using computed tomography data from a series of surgically treated patients.@*Methods@#In this study, 504 patients with intertrochanteric fractures were retrospectively analyzed. Fracture patterns were graded according to Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification. Fracture lines were transcribed onto proximal femoral templates and graphically superimposed to create a compilation of fracture maps that were subsequently divided into anterior, posterior, lateral, and medial fracture maps to create a three-dimensional (3D) pattern by reducing fragments in the 3D models. The fracture maps were then converted into frequency spectra. The major fracture patterns were assessed by focusing on the lateral femoral wall, lesser trochanter, intertrochanteric crest, and inner cortical buttress.@*Results@#Anterior, posterior, lateral, and medial fracture maps were created. The majority of fracture lines (85.9%, 433/504) on the anterior maps were along the intertrochanteric line where the iliofemoral ligament was attached. In the medial plane, the majority of fracture lines (49.0%, 247/504) shown on the frequency spectrum included the turning point involving the third quadrant. In the posterior plane, the majority of fracture lines (52.0%, 262/504) involved the intertrochanteric crest from the greater to the lesser trochanter. In the lateral plane, the majority of fracture lines (62.7%, 316/504) involved the greater trochanter at the gluteus medius attachment.@*Conclusions@#The fracture patterns observed in the present study might be used to describe morphologic characteristics and aid with management strategies. Further classifications or modifications that incorporate the fracture patterns identified in this study may be used in future research.
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Aim: The aim of the study was to compare the flexibility of three different splints and to determine their peak load failure in fracture pattern. Material and Methods: Three different splints (wire-composite, single layer fibre glass and fibre reinforced Everstik splint) were adapted to the extracted Human incisors, placed in a non-rigid fashion on the experimental dental models designed for the study. Stress analysis was conducted on the test specimens by applying both static axial and 45° oblique force with linear increasing intensity ranging from 0-50N and 0-30N respectively both with and without splints using universal testing machine. For each loading direction, the energy required to modify the position of the teeth at increasing applied forces was recorded for specimens with and without splints and the difference between two values (∆E) was determined, which corresponds to the rigidity of the materials. Results: For both axial and oblique tests, fibre reinforced splint had shown least ∆E values (0.02±0.08 in axial, 0.01±4.05 in oblique) while wire-composite had shown highest ∆E values (0.67±2.56 in axial, 1.42±5.16 in oblique). Conclusions: Fibre reinforced splint could be an ideal alternative for splinting traumatized teeth, as it exhibits a lower energy variation needed for deformation and conducive to optimal periodontal healing during immobilization.
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STUDY DESIGN: Retrospective study. OBJECTIVES: To analyze the influence of fracture patterns and the result of bone mineral density on cement leakage after percutaneous vertebroplasty for osteoporotic vertebral compression fractures. SUMMARY OF LITERATURE REVIEW: Leakage of bone cement after vertebroplasty has known to be related with the direction of cortical disruption of fractured vertebral body and low bone mineral density (BMD). MATERIALS AND METHODS: One hundred eighty-two patients with osteoporotic vertebral compressions were studied from January 2009 to August 2013. The patients' fracture levels and patterns were compared. Among them, the cement leakage patterns were analyzed in 105 patients who had undergone vertebroplasty. The findings were compared with fracture patterns including cortical disruption and BMD. RESULTS: Seventy-five cases of cement leakage were observed. Among them, intradiscal leakage was the most common type of leakage. In the patient group with low BMD, there was a high incidence of lower and posterior cortical disruption in the fractures. Patients with posterior cortical disruption demonstrated a higher incidence of leakage into the spinal canal and anterior cortex. No significant correlation was observed between fracture patterns and leakage. CONCLUSIONS: A surgeon should use caution in performing vertebroplasty in patients with low BMD and posterior disruption of the vertebral cortex.
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Humans , Bone Density , Fractures, Compression , Incidence , Osteoporosis , Retrospective Studies , Spinal Canal , VertebroplastyABSTRACT
PURPOSE: To discriminate the characteristics between reverse obliquity fractures in the elderly and that of young adults using three-dimensional computed tomography (3D CT). MATERIALS AND METHODS: Eighteen patients who had reverse obliquity intertrochanteric fractures were enrolled from January 2007 to March 2012. The fracture pattern was analyzed using the 3D CT. The area showing low density (bone defect) of trochanter and femoral neck region was measured. Patients were divided into two groups: Group I, less than 65 years old and Group 2, 65 years and over. RESULTS: In all 9 cases of group 1, the proximal fragment had a 'V' shape with an average of 5.6 cm below the vastus ridge; however, the fracture of 8 cases (88.97%) in group 2 had a 'Lambda' shape of the distal fragment at the level of vastus ridge and an additional fracture line extending to the greater trochanter tip. The bone defect volume of the trochanter and femoral neck region was larger significantly in group 2 than in group 1. CONCLUSION: Reverse obliquity intertrochanteric fracture in the elderly demonstrated a pattern of bursting fracture with 4 parts, which had different patterns from that of young patients. We believe that the larger volume of bone defects resulted in the difference of fracture patterns between the two groups.
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Aged , Humans , Young Adult , Femur , Femur Neck , Hip FracturesABSTRACT
Objective To investigate fracture resistance and fracture patterns of maxillary anterior endodontically treated teeth restored with two different shapes of glass fiber post systems.Methods Twenty-four human sound maxillary anterior teeth of similar size were collected,and randomly divided into 3 groups,8 teeth each.After endodontical treatment,they were given the following treatments:Group A:parallel glass fiber posts (coltene parapost fiber lux) and composite core;Group B:taper glass fiber posts (coltene parapost taper lux) and composite core; Group C (control group):intact endodontically treated teeth.Teeth in Groups A and B reserved 2 mm dentin ferrule.Then the teeth were prepared and restored with IPS e.max Press all ceramic crowns.All the teeth were embedded in acrylic resin 2 mm below the cementoenamel junction (CEJ),with the silicon impression material stimulating periodontal membrane.All the specimen were loaded under a universal testing machine,at the palatal junction of incisor third and middle third,with an angle of 135 degree to the longitudinal axis of the tooth until fracture occurred,at a cross-head speed of 1.0 mm/min.Fracture loads and patterns were recorded.Statistical analysis was performed using SPSS software.Results The mean fracture loads in the three groups were as follows:(468.8±142.5) N,(440.2±202.7) N,and (459.0±147.6) N,respectively.There was no significant difference in fracture loads among groups (P＞0.05).The incidence of unfavorable fracture in Group A was higher than Groups B and C.Conclusions There is no significant difference in fracture strength between parallel and taper fiber post groups.However,the group with parallel fiber posts demonstrates a higher risk of unfavorable fracture than the group with taper fiber posts,which indicates that taper fiber posts are more favorable to preserve the remaining tooth structure.
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@#Objective To analyze the constituent ratio and clinical characteristics of spine trauma and spinal cord injury of the survivors in the Sichuan earthquake.Methods198 cases wounded in the Sichuan earthquake were divided into four groups according to age for collecting the type of fracture, nerve damage, spinal fractures combined injuries of data from multiple sites, analyzing their clinical characteristics.ResultsFracture types are most common compression fractures (49.3%), followed by the burst fractures (45.9%). 105 of them had spinal cord injury, ASIA grade: A grade: 20 cases, B Grade: 18 cases, C grade: 25 cases, D Grade: 42 cases. 41 cases had combined injury. T12, L1, and L2 vertebral fractures were common types.ConclusionCompression fractures and burst fractures as spinal injuries occurred commonly in Sichuan earthquake mainly in the 18～65 years old, and spinal cord injury accounted for 53.03% spinal injury.
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PURPOSE: The purpose of this study is to compare the effect of two fiber post systems and one metal cast post system on the fracture strength and fracture pattern of crowned, endodontically treated teeth with 2 mm-height of the reamining tooth structure. MATERIALS AND METHODS: A total of 36 recently extracted sound human mandibular premolars were selected. Each tooth structure of the crown portion except 2mm-height of the one above the cementoenamel junction was removed. After being endodontically treated, they were randomly distributed into 3 groups: group 1, restored with quarts fiber post(D.T. Light-Post), group 2, with glass fiber post(FRC Postec), and group 3, metal cast post and core. All teeth were fully covered with nonprecious metal crowns. Each specimen was embedded in an acrylic resin block and then secured in a universal load-testing machine. A compressive load was applied at a 130 degree angle to the long axis of the tooth until fractured, at a crosshead speed 20mm/min. The highest fracture loads were measured and recorded as the fracture strength of each specimen. Fracture areas were measured on the mid-buccal and mid-lingual point from the crown margins. One-way analysis of variance and Turkey test were used to determine the statistic significance of the different fracture loads and areas among the groups(p.05). The mean fracture area of the fiber post was closer to the crown margin than that of the metal cast post and core(p<.05). The metal cast post showed unrestorable and catastrophic fracture patterns. CONCLUSION: Within the limitations of this study, fracture loads with any statistically significant difference were not recorded for endodontically treated teeth restored with two fiber posts and the metal cast post. But teeth restored with the fiber posts typically showed the fracture pattern close to the crown margin, which was almost restorable.